Around 187,000 youngsters - roughly half the school-age Syrian children in the country - are not going to classes, the agency said, as it launched a documentary on their situation.

"Poverty, social exclusion, insecurity and language barriers are preventing Syrian children from getting an education, leaving an entire generation disadvantaged, impoverished and at risk of being pushed into early marriage and child labor," said UNICEF Lebanon Representative Tanya Chapuisat.

After nearly six years of war, more than half Syria's people have fled their homes, including more than a million to Lebanon.

One boy in the documentary, 14-year-old Jomaa, told UNICEF he had forgotten how to read or write since dropping school and taking up $2-a-day job.

Mohamad, aged 11, said he had not been to school since arriving in Lebanon four years ago, and his parents had sent him to work.

Abeer, aged 13, said she left Syria six years ago and no longer went to classes because there was no safe transport to take her.